Typical approaches to alerting individuals in a particular geographic area, for example campus alerting at a college or university, involve sending generic broadcast alerting messages pertaining to an emergent situation. For example, a broadcast message might be sent to all subscribers to a campus alerting system. Such a message might contain generic information or instructions pertaining to an emergent situation taking place somewhere on the campus. This type of alerting, however, has several shortcomings. For example, in a campus alerting scenario, the alerting message may not reach all persons who may be affected, such as visitors, attendees at a campus sporting event, or other non-subscribers. Further, sending a generic message to all subscribers may cause needless panic, for example alerting subscribers at a crowded sporting event when the emergent situation is occurring in a remote area distant from the sports stadium. Delivering a generic message might also put innocents in harm's way, for example if an alerting message describing an escape route was delivered to a terrorist holding hostages, thereby facilitating cutoff of the escape route. Additionally, broadcast alerting systems are costly, both in terms of the overhead involved in maintaining lists of subscribers, and in terms of the network resources consumed. Large scale broadcasts may overburden network components, resulting in failed delivery or message loss.